KR20010050161A - Liquid Silicone Rubber Compositions For Coating and Cloths For Airbag - Google Patents

Abstract

PURPOSE: To obtain a liquid silicone rubber composition for coating having excellent penetrability and adhesion and further thin-film coating properties without using a diluting solvent, reduced in surface tacky feeling and effectively usable especially as a coating agent for air bags. CONSTITUTION: This solventless type liquid silicone rubber composition for coating comprises (A) an organopolysiloxane containing >= 2 alkenyl groups in one molecule, (B) an organohydrogenpolysiloxane having >= 2 hydrogen atoms bound to silicon atom in one molecule, (C) a wet-method silica having 150-250 m2/g specific surface area on the average according to the BET method, <= 20 μm average particle diameter and <= 0.35 wt.% Na ion content expressed in terms of Na2O, (D) an adhesive component and (E) a platinum-based catalyst.

Description

Liquid Silicone Rubber Compositions For Coating and Cloths For Airbag}

The present invention relates to a liquid silicone rubber composition for a solvent-free coating, and more particularly, to an air bag coating such as a vehicle, which is excellent in thin film coating property with no solvent and can withstand stretching impact, especially at high temperatures. It relates to a suitable liquid silicone rubber composition and cloth for airbags.

Recently, airbags have been put into practical use as safety devices for passenger protection of automobiles. Such airbags generally consist of fabrics coated with chloroprene rubber on nylon fabrics.

However, the fabric coated with this chloroprene rubber is difficult to reduce the weight, and in particular, there is a drawback that the physical properties deteriorate with aging. In addition, an airbag fabric coated with a silicone rubber composition has recently been proposed (see Japanese Patent Laid-Open No. 63-78744, Japanese Patent Laid-Open No. 3-243442, and Japanese Patent No. 2571986). Airbag fabrics coated with these silicone rubber compositions have the advantage of excellent high temperature properties. By the way, when apply | coating these silicone rubber compositions to synthetic fiber fabrics for airbags, such as nylon 66, it had a drawback that it is essential to use an organic solvent for dilution in order to apply | coat uniformly thinly and to acquire sufficient adhesive force to a fabric. That is, these silicone rubber compositions have a problem in that they must be diluted with an organic solvent such as toluene, xylene, etc. in order to secure thin film coating property and permeability to fabric.

In addition, Japanese Patent No. 2571986 proposes to introduce a silicone resin having SiO ₄ units as a liquid solvent-free composition, and Japanese Patent Laid-Open No. 7-90777 proposes using a hydrophobic silica as a filler. However, even with these proposals, when the adhesive component is introduced to achieve firm adhesion with the fabric, the thixotropy is increased, which is 40 µm, which is desired as a coating thickness of the silicone composition on the fabric in order to reduce or reduce the cost. Alternatively, there has been a difficulty in that an application thickness of 20 µm or less cannot be achieved. Moreover, the reduction of the surface tag after silicon film formation was also not enough.

The present invention has been made to improve the above circumstances, and can form a coating film having excellent permeability and adhesiveness and excellent thin film coating property without using a diluent solvent, and having a reduced surface tack (adhesiveness). It is an object of the present invention to provide a fabric for airbags having a liquid silicone composition for solvent-free coating and a coating film thereby.

<Means for solving the problem and embodiments of the invention>

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to achieve the said objective, the present inventors have found that organopolysiloxane containing two or more alkenyl groups in one molecule, and two or more hydrogen atoms (ie, SiH groups) bonded to silicon atoms in one molecule. In the liquid silicone rubber composition for coating containing organohydrogenpolysiloxane, wet silica, adhesive component, and platinum-based catalyst, the wet silica has a BET specific surface area of 150 to 250 m 2 / g on average and an average particle diameter (secondary aggregated mass). ) Is 20 μm or less, and the specific wet silica in which Na ions in the silica is 0.35 wt% or less as Na ₂ O exhibits good permeability and thin film coating property with respect to the synthetic fiber fabric for airbags in a solvent-free manner. It has been found that the tackiness) is reduced, and at the same time, the firm adhesive strength is achieved, and thus the present invention has been completed.

Therefore, the present invention

(A) organopolysiloxane containing two or more alkenyl groups in one molecule,

(B) an organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms in one molecule,

(C) wet silica having a specific surface area by the BET method on an average of 150 to 250 m 2 / g, an average particle diameter of 20 µm or less, and a Na ion content of 0.35% by weight or less as Na ₂ O,

(D) an adhesive component, and

(E) It provides the liquid silicone rubber composition for coating of a non-solvent type containing a platinum type catalyst, and the cloth for airbag in which the coating film by this composition was formed.

Hereinafter, the present invention will be described in more detail.

Organopolysiloxane of (A) component used for this invention is a component which becomes the subject of this composition, and since it becomes a silicone rubber coating film which has rubber elasticity after hardening of this composition, two or more silicon atom bonds in 1 molecule It is necessary to have an alkenyl group.

It is preferable that such organopolysiloxane has an average of 2 or more alkenyl groups in 1 molecule represented by the following average formula (1).

R ¹ _a SiO _{(4-a) / 2}

In formula, R <^1> is a substituted or unsubstituted monovalent hydrocarbon group, Preferably 0.01-10 mol% of R <^1> is an alkenyl group and a is a positive number of 1.9-2.4.

Here, R ¹ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 12 carbon atoms, especially 1 to 8 carbon atoms bonded to a silicon atom, for example, methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group cycloalkyl groups such as alkyl groups such as tert-butyl group, pentyl group, neopentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group and dodecyl group, cyclopentyl group, cyclohexyl group and cycloheptyl group, Aryl such as vinyl group, allyl group, propenyl group, isopropenyl group, butenyl group, isobutenyl group, hexenyl group, cyclohexenyl group and the like, alkenyl group, phenyl group, tolyl group, xylyl group, naphthyl group and biphenyl group An aralkyl group such as a group, a benzyl group, a phenylethyl group, a phenylpropyl group, a methylbenzyl group, or a chloromethyl group in which part or all of the hydrogen atoms in these hydrocarbon groups are substituted with a halogen atom such as F, Cl, Br, or a cyano group, 2-bromoethyl group, 3,3,3-trifluoropropyl , And 3-chloropropyl group, cyanoethyl group.

In this case, it is preferable that the said organopolysiloxane is 90 mol% or more of the substituted or unsubstituted monovalent hydrocarbon group shown by said R <^1> is a methyl group. In addition, at least 2 average is an alkenyl group, Preferably, 0.01-10 mol%, More preferably, 0.02-5 mol% of all R <^1> groups are alkenyl groups. When the ratio of alkenyl groups is too small, the curability of the composition obtained will fall, and when too large, physical properties, such as tensile strength, tear strength, and elongation, of hardened | cured material will fall. In addition, the alkenyl group may be bonded to the silicon atom at the terminal of the molecular chain or to the silicon atom in the molecular chain, and may be present at both. Moreover, as an alkenyl group, a vinyl group is preferable and as a group other than a methyl group and a vinyl group, a phenyl group and a 3,3,3- trifluoropropyl group are preferable.

In Formula 1, a is a positive number of 1.9 to 2.4, preferably 1.95 to 2.05, and the molecular structure of the organopolysiloxane is basically a straight chain composed of repetition of diorganosiloxane units. Although it is preferable to have an alkenyl group at the molecular chain sock end, it may have a branched structure including R ¹ SiO _3/2 units or SiO _4/2 units at a portion thereof. In addition, the organopolysiloxane preferably has a molecular chain terminal sealed with a triorganosilyl group such as trivinylsilyl group, methyldivinylsilyl group, dimethylvinylsilyl group or trimethylsilyl group.

As for the viscosity of this organopolysiloxane, when the viscosity in 25 degreeC is 100 centipoise or more (usually 100 to 50,000 centipoise), the viscosity in 25 degreeC is considered, considering the silicone rubber coating film strength, compounding workability, etc. More preferred are those of 400 to 10,000 centipoise, especially those of 500 to 5,000 centipoise.

As a specific example of (A) component, for example, the succinic dimethyl vinyl siloxy group blocking dimethylpolysiloxane, the succinic dimethyl vinyl siloxy group blocking dimethylsiloxane, methyl vinyl siloxane copolymer, and the succinic dimethyl vinyl siloxy group blocking dimethyl siloxane methylphenylsiloxane air Coalescence, etc. are mentioned.

The organohydrogenpolysiloxane of (B) component is mix | blended with the composition of this invention as a hardening | curing agent (crosslinking agent) of the alkenyl group containing organopolysiloxane (base polymer) of the said (A) component. That is, the organohydrogenpolysiloxane acts as a crosslinking agent, in which the alkenyl group bonded to the silicon atom in the base polymer and the hydrogen atom (ie, SiH group) bonded to the silicon atom in the organohydrogenpolysiloxane are used as the catalyst. In the presence, it crosslinks and hardens | cures by hydrosilylation addition reaction. The organohydrogenpolysiloxane has at least two hydrogen atoms (ie, SiH groups) bonded to at least two, preferably three or more silicon atoms in one molecule, and is preferably liquid at room temperature represented by the following average formula (2). .

R ² _b H _c SiO _{(4-bc) / 2}

In formula, R <^2> is a C1-C10 substituted or unsubstituted monovalent hydrocarbon group, b is 0.7-2.1, c is 0.001-1.0, and b + c is a positive number satisfying 0.8-3.0.

Herein, R ² is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms, in particular 1 to 8 carbon atoms, and the same groups as those exemplified in R ¹ above, preferably those containing no aliphatic unsaturated bonds, In particular, an alkyl group, an aryl group, an aralkyl group, a substituted alkyl group, for example, a methyl group, an ethyl group, a propyl group, a phenyl group, a 3,3,3-trifluoropropyl group, etc. may be mentioned as preferable ones. b is 0.7 ≦ b ≦ 2.1, preferably 1 ≦ b ≦ 2, c is a positive number of 0.001 ≦ c ≦ 1.0, preferably 0.01 ≦ c ≦ 1.0, and b + c is 0.8 ≦ b + c ≦ 3.0, preferably For example, 1 ≦ b + c ≦ 2.4, and the molecular structure may be any one of linear, cyclic, branched, and three-dimensional network, and the SiH group may be present at the end of the molecular chain or in the molecular chain. It may be present in both. Although there is no restriction | limiting in particular in molecular weight, It is preferable that the viscosity in 25 degreeC is the range of 1-1,000 centipoise (cp), especially 3-500 centipoise (cp).

Specific examples of the organohydrogenpolysiloxane of the component (B) include 1,1,3,3-tetramethyldisiloxane, methylhydrogen cyclic polysiloxane, methylhydrogensiloxane dimethylsiloxane cyclic copolymer, and sock end trimethylsiloxane Timing block methylhydrogen polysiloxane, sock end trimethylsiloxy group blockade dimethylsiloxane methylhydrogensiloxane copolymer, sock end dimethylhydrogensiloxy group blockade dimethylpolysiloxane, sock end dimethylhydrogensiloxy group blockade dimethylsiloxane, methylhydrogensiloxane Copolymerization, sock end trimethylsiloxy group blockade methylhydrogensiloxane diphenylsiloxane copolymer, sox end trimethylsiloxy group blockade methylhydrogensiloxane diphenylsiloxane dimethylsiloxane copolymer, (CH ₃ ) ₂ HSiO _1/2 unit copolymers composed of SiO _4/2 units, (CH _{3) 2} HSiO _1/2 units and (CH _{3) 3} SiO _1/2 units Copolymers composed of SiO _4/2 units, (CH ₃₎ may be mentioned ₂ HSiO _1/2 units and SiO _4/2 units and (C ₆ H _{5) 3} SiO _1/2 units, such as copolymers consisting of.

Among them, it can be confirmed that the fact that the CH ₃ (H) SiO unit occupies half or more of all the siloxane units matches with the adhesive component of component (D) described later, which is effective in improving the adhesion to the fabric.

In the composition of the present invention, wet silica is blended as the component (C). This wet silica (for example, silica synthesized by a wet manufacturing method such as precipitated silica) is generally used as a filler for silicone rubber, but in the present invention, it is used for coating applications, particularly coating applications for fabrics for airbags. As a suitable, the specific surface area by BET method is an average of 150-250 m <2> / g, and an average particle diameter (primary particle of a wet silica is very small, it is actually aggregated, and the particle diameter of this secondary aggregated mass is normally used as an average particle diameter). is any) is not more than a 20 ㎛, the Na ion in the silica is not more than 0.35% by weight in terms of the required Na ₂ O.

That is, when using wet silica as a main filler, in order to make it a liquid-free solvent type, the specific surface area by BET method needs to be 150-250 m <2> / g on average. If it is smaller than 150 m 2 / g, the physical strength cannot be obtained, and if it is larger than 250 m 2 / g, the viscosity of the composition is increased to achieve a coating film of 40 m or less. In the range of 150 to 250 m 2 / g, it is possible to obtain an appropriate viscosity for coating, and also, as a characteristic, it is almost thixotropic even if an adhesive component, which is component (D) described later, is added at all unlike a case of using dry silica. This does not increase and the desired coating performance and adhesiveness can be obtained without accompanied by a viscosity increase.

Further, in order to achieve a coating thickness of 40 mu m or less, preferably 20 mu m or less, which is desired for the airbag, it is necessary to select an average particle diameter of 20 mu m or less, preferably 10 mu m or less. In addition, the lower limit is not particularly limited, but is at least 0.1 μm, in particular at least 0.1 μm. In addition, this average particle diameter can be normally calculated | required as a weight average value (or median diameter) by a laser beam diffraction method.

Moreover, when this composition is apply | coated to a fabric, anti-inflammatory property is calculated | required as a function of an airbag. In general, wet silica is produced from soda silicate, and it is well known that sodium ions remain as impurities. When compounding and filling these into a silicone rubber composition, what is called flame retardance falls. Therefore, in order to ensure flame retardancy while maintaining the above-described characteristic characteristic of wet silica, it is necessary that sodium ions in the silica be 0.35% by weight or less, preferably 0.30% by weight or less as Na ₂ O.

The adhesive component of (D) component is an essential component in order to improve the adhesiveness to the synthetic fiber fabric for airbags of this composition. The component is different depending on the case where the fabric is nylon or polyester fiber, but in the case of nylon fabric, epoxy group-containing compounds such as glycidyl groups, for example, γ-glycidoxypropyltrimethoxysilane and γ-glycid Epoxy group-containing organoalkoxysilanes such as doxypropylmethyldiethoxysilane and 3,4-epoxycyclohexylethyltrimethoxysilane; Epoxy group-containing organopolysiloxanes such as epoxy group-containing organopolysiloxane having a vinyl group and alkoxy group of silicon atom bond, epoxy group-containing organopolysiloxane having silicon atom-bonded hydrogen atom, epoxy group-containing organopolysiloxane having silicon atom-bonded hydrogen atom and alkoxy group, Glycidyl (meth) acrylate, allyl glycidyl ether, and the like show good results for adhesion.

In the case where the raw material is polyester, γ- (meth) acryloxypropyltrimethoxysilane, vinyltrialkoxysilane, or a siloxane which is a partial hydrolyzate thereof, a silane or siloxane having a silicon atom-bonded hydrogen atom and an alkoxysilyl group, or phenyl The compound etc. which have a skeleton and a silicon atom bonded hydrogen atom are mentioned as a suitable example.

As a specific example of the said epoxy group containing compound, the following compounds are illustrated.

Provided that Me represents a methyl group and Vi represents a vinyl group.

As the addition reaction catalyst (E), a single element, a compound, a complex thereof, and the like containing a platinum group metal as a catalyst metal can be used in the composition of the present invention. Specifically, platinum-based catalysts such as platinum black, platinum chloride, chloroplatinic acid, reactants of chloroplatinic acid with monohydric alcohols, complexes of chloroplatinic acid with olefins, complexes of chloroplatinic acid with vinylsiloxane, and platinum-based catalysts such as platinum bisacetoacetate Palladium catalysts such as tetrakis (triphenylphosphine) palladium, dichlorobis (triphenylphosphine) palladium, rhodium catalysts such as chlorotris (triphenylphosphine) rhodium and tetrakis (triphenylphosphine) rhodium Etc. can be mentioned.

In addition, in the composition of the present invention, for the purpose of improving physical properties such as tensile strength and tear strength of the cured product, R ¹ SiO _3/2 unit (R ¹ is the same as above) and (or ) Contains a soluble alkenyl group in a silicone oil which contains SiO _4/2 units and may contain one or more selected from R ¹ ₃ SiO _1/2 units and R ¹ ₂ SiO _2/2 units as necessary. Three-dimensional network silicone resin can be blended.

Here, in the present invention, the compounding amount of the organohydrogenpolysiloxane of the component (B) is 0.1 to 50 parts, in particular 1 to 20 parts with respect to 100 parts (parts by weight) of the organopolysiloxane of the component (A). Preferably, the wet silica of component (C) is 1 to 30 parts, in particular 3 to 20 denier, based on 100 parts of component (A), and the adhesive component of component (D) is preferably 100 parts of component (A). 0.1-30 parts, especially 0.1-5 parts are preferable. Moreover, it is preferable that the compounding quantity of the silicone resin of (F) component is 0-50 parts with respect to 100 parts of (A) component, Especially 0-30 denier. In this case, the molar ratio of the total SiH groups in the composition to the total alkenyl groups in the composition (i.e., to the alkenyl groups bonded to the silicon atoms in the component (A) (and optionally the component (D), component (F)) It is preferable that the molar ratio of the hydrogen atom (SiH group) couple | bonded with the silicon atom in (B) component (and optionally (D) component) is 0.9-20, especially 0.9-5, and (A) component 1 It is preferable that the sum total of the alkenyl group couple | bonded with the silicon atom contained in a molecule | numerator, and the SiH group contained in 1 molecule of (B) component is 5 or more.

Moreover, it is preferable to use the addition amount of (E) component within the range of 0.1-500 ppm, Preferably it is 1-50 ppm as a platinum type metal with respect to (A) component. This is because the reaction does not proceed sufficiently below 0.1 ppm, and it is uneconomical if it exceeds 500 ppm.

The composition of the present invention is, in addition to the above components (A) to (F), 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and phenyl moiety as reaction regulator components. Alkyn alcohols such as tinol; Enyne compounds, such as 3-methyl-3- pentene- 1-yne and 3, 5- dimethyl- 3-hexene- 1-yne, tetramethyl tetrahexenyl cyclo tetrasiloxane, benzotriazole, etc. are used. In addition, pigments, heat-resistant agents, and flame retardant enhancers (titanium dioxide, iron oxide 2,3, iron oxide 3,4, carbon black, cerium oxide, and cerium hydroxide, which are generally useful for silicone rubber, are provided as necessary without impairing the object of the present invention. Etc.), and the above components can be easily prepared by uniformly kneading the above components with a mixer such as a kneader mixer, a pressure kneader mixer, a loss mixer, or the like.

In addition, the composition of the present invention is used as a solvent-free, the viscosity of 25 ℃ is preferably 500 to 80,000 centipoise (cp), in particular 1,000 to 10,000 centipoise (cp).

The composition of the present invention can be coated on a synthetic fiber fabric for an air bag, put into a hot air drying furnace, and cured by heating to form a liquid silicone rubber coated fabric for an air bag. Applying this to the synthetic fiber fabric for airbags, the silicone rubber coating film can sufficiently penetrate the synthetic fiber fabric for airbags and be uniformly coated in a thin film without staining. The coating amount of this silicone rubber composition is usually 40 g / m ² or less, in particular 5 to 40 g / m ² , and more particularly 10 to 30 g / m ² . And after heat-hardening, it is excellent in flexibility, and at the same time, a silicone rubber coating film and the synthetic fiber fabric for airbags are firmly combined and integrated, the adhesive strength can fully endure the scrubbing test, and adapts also to a flame retardancy test. In addition, the fabric for the airbag formed by coating the composition of the present invention has no deterioration of the folded portion during airbag storage, and at the same time, the silicone rubber coating film does not peel off due to severe abrasion during airbag operation.

Moreover, as a synthetic fiber fabric for airbags, For example, polyamide fiber fabrics, such as nylon 6, nylon 66, nylon 46, aramid fiber fabric, polyester fiber fabric represented by polyalkylene terephthalate, polyetherimide fiber fabric, Sulfone-based fiber fabrics, carbon fiber fabrics, and the like. Of these synthetic fiber fabrics for airbags, nylon 66 fiber fabrics are most preferred.

Further, the coating method and the like are not particularly limited, and as the curing conditions after coating, the conditions of usually 30 seconds to 3 minutes at 150 to 200 ° C., particularly at 30 to 80 seconds at 150 to 200 ° C. may be adopted.

<Example>

Hereinafter, although an Example and a comparative example are given and this invention is demonstrated concretely, this invention is not limited to the following Example. In addition, in the following example, "part" is a "weight part", a viscosity is a value in 25 degreeC, and cp represents a centipoise. In addition, Me represents a methyl group and Vi represents a vinyl group.

<Example 1>

Wet silica A (specific surface area 190 m 2 / g, average particle diameter 10 μm, Na ions in silica as Na ₂ O as Na ₂ O) in 100 parts of dimethylpolysiloxane having a viscosity of 1,500 cp whose molecular chain ends were sealed with dimethylvinylsiloxy groups. 19 parts and 2 parts of terminal dimethylhydroxysilyl group block | blocked dimethylpolysiloxane which have the average number of siloxanes were mixed until it became uniform with a Ross mixer, and further heat-processed to 150 degreeC under reduced pressure, and the fluid liquid silicone base was produced. Subsequently, to 100 parts of this liquid silicone base, 5.2 parts of methylhydrogenpolysiloxane represented by the average molecular formula Me ₃ SiO (MeHSiO) ₆ (Me ₂ SiO) ₄ SiMe ₃ , and 0.4 parts of a complex of chloroplatinic acid and divinyltetramethyldisiloxane. (Platinum concentration 0.4% by weight), 0.3 part of 3,5-dimethyl-1-hexyn-3-ol as a curing control agent, and 1 part of γ-glycidoxypropyltrimethoxysilane as an adhesion aid were added and mixed uniformly, A liquid silicone rubber composition for coating was prepared. The viscosity of this composition was 4,500 cp.

This was then coated onto a nylon 66 fiber fabric (210 denier) and cured by heating at 180 ° C. for 1 minute. Here, the coating method for the fabric is coated with a knife coater so that the liquid silicone rubber composition can be uniformly coated without application stain, and heat-cured at 180 ° C. for 1 minute in an oven to make a silicone rubber coating cloth. The following test was done about this.

Scott Rub Exam

After performing a scrubbing test 1000 times at a pressing pressure of 2 kgf using a Scott rub tester, the peeling state on the cloth surface of the silicone rubber coated thin film was visually confirmed.

Tack

Tack feeling (adhesiveness) on the coating film surface was confirmed by finger touch.

Flame retardant

The test of flame retardance confirmed the flame retardance by the FMVSS302 combustion test.

permeability

After cutting the synthetic fiber fabric for airbag into 2 cm wide and 10 cm long strips vertically, the bottom 0.5 mm was immersed in the liquid silicone rubber composition, and the liquid silicone rubber composition was left at room temperature for 24 hours. The distance penetrating this fabric was measured.

The measurement results of these properties are shown in Table 1 below.

<Example 2>

Vinyl group-containing methylpolysiloxane resin consisting of Vi (Me) ₂ SiO _1/2 units, Me ₃ SiO _1/2 units and SiO _4/2 units in 106.9 parts of the liquid silicone rubber composition prepared in Example 1 (Vi group content 5.5 %, Vi (Me) ₂ SiO _1/2 unit and the ratio of Me ₃ SiO _1/2 unit and SiO _4/2 unit 0.85) 10 parts were added to prepare the liquid silicone rubber composition for coating in the same manner, and the same It was coated on nylon 66 fiber fabric (210 denier) and heat cured at 180 ° C. for 1 minute. The characteristics were also tested in the same manner as in Example 1. The results are written together in Table 1 below.

<Comparative Example 1>

Liquid silicone rubber composition for coating in the same manner as in Example 1 using 19 parts of wet silica B (specific surface area 120 m 2 / g, average particle diameter 15 µm, Na ions in silica as Na ₂ O 0.46 wt%) instead of wet silica A Was prepared and coated on nylon 66 fiber fabric (210 denier) in the same manner and cured by heating at 180 ° C. for 1 minute. The characteristics were also tested in the same manner as in Example 1. The results are written together in Table 1 below.

<Comparative Example 2>

Vinyl group-containing methylpolysiloxane resin consisting of Vi (Me) ₂ SiO _1/2 units, Me ₃ SiO _1/2 units and SiO _4/2 units in 106.9 parts of the liquid silicone rubber composition prepared in Comparative Example 1 (Vi group content 5.5 %, Vi (Me) ₂ SiO _1/2 unit and the ratio of Me ₃ SiO _1/2 unit and SiO _4/2 unit 0.85) 10 parts were added to prepare the liquid silicone rubber composition for coating in the same manner, nylon 66 fiber fabrics (210 deniers) were coated and heat cured at 180 ° C. for 1 minute. The characteristics were also tested in the same manner as in Example 1. The results are written together in Table 1 below.

Example 1 Example 2 Comparative Example 1 Comparative Example 2 Coating amount (g / m ² ) 23 24 26 29 Scott Rub Exam pass pass pass pass Tack none none none has exist FMVSS302 combustion test pass pass fail fail permeability 2.5 2.4 2.4 2.3

<Example 3>

Wet silica C (specific surface area 186 m 2 / g, average particle diameter 14 μm, Na9 in silica as Na ₂ O as Na ₂ O) in 100 parts of dimethylpolysiloxane with a viscosity of 600 cp whose molecular chain sock end was sealed with dimethylvinylsiloxy group 11 parts and 5 parts of hexamethyldisilazane and 2 parts of water were added as a silica surface treatment agent, mixed until uniform with a Loss mixer, and further heated to 150 ° C. under reduced pressure to prepare a fluid liquid silicone base. Subsequently, to 100 parts of this liquid silicone base, 6.2 parts of methylhydrogenpolysiloxane represented by the average molecular formula Me ₃ SiO (MeHSiO) ₂₀ SiMe ₃ , and 0.35 parts of a complex of chloroplatinic acid and divinyltetramethyldisiloxane (platinum concentration 0.4% by weight) ), 0.3 part of 3-methyl-1-butyn-3-ol as a curing control agent, and 1 part of 3,4-epoxycyclohexylethyltrimethoxysilane as an adhesion aid are added and mixed uniformly, and the liquid silicone rubber composition for coating Was prepared. The viscosity of this composition was 1,600 cp.

This was coated onto a nylon 66 fiber fabric (210 denier) in the same manner as in Example 1, and tested for properties in the same manner. The results are shown in Table 2 below.

<Comparative Example 3>

Liquid silicone rubber composition for coating in the same manner as in Example 3 using 19 parts of wet silica D (specific surface area 270 m 2 / g, average particle diameter 14 μm, Na ions in silica 0.39 wt% as Na ₂ O) instead of wet silica C Were prepared and coated on the same nylon 66 fiber fabric (210 denier) and heat cured at 180 ° C. for 1 minute. The characteristics were also tested in the same manner as in Example 1. The results are written together in Table 2 below.

<Comparative Example 4>

In Example 3, instead of wet silica C, dry silica (Aerosil 200, Nippon Aerosil Smoked Silica) was used in the same manner to prepare a liquid silicone rubber composition for coating, but the viscosity increased. It was similarly coated on nylon 66 fiber fabric (210 denier) but could not be coated on thin films. The characteristics were also tested in the same manner as in Example 1. The results are written together in Table 2 below.

Example 3 Comparative Example 3 Comparative Example 4 Coating amount (g / m ² ) 20 24 105 Scott Rub Exam pass pass pass Tack none none has exist FMVSS302 combustion test pass fail pass permeability 2.9 2.8 1.9

<Example 4 and Comparative Example 5>

1 part of 3,4-epoxycyclohexylethyltrimethoxysilane was changed to (gamma)-(meth) acryloxypropyl trimethoxysilane in the adhesion | attachment aid of the liquid silicone rubber composition manufactured in Example 3 and the comparative example 3, and other The raw material is the same, the manufacturing method is also applied to the liquid silicone rubber composition (Example 4, Comparative Example 5) prepared in the same manner as in Example 1 to the polyester fiber fabric (210 denier), respectively, to make a silicone rubber coating cloth The characteristic was measured. The results are shown in Table 3 below.

Example 4 Comparative Example 5 Coating amount (g / m ² ) 22 25 Scott Rub Exam pass pass Tack none none FMVSS302 combustion test pass fail permeability 3.1 3.0

The composition of the present invention has excellent permeability and adhesiveness without using a diluent solvent, is excellent in thin film coating property, and also reduces surface tagging feeling, and is particularly effective as a coating agent for airbags.

Claims (4)

(A) organopolysiloxane containing two or more alkenyl groups in one molecule, (B) an organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms in one molecule, (C) wet silica having a specific surface area by the BET method on an average of 150 to 250 m 2 / g, an average particle diameter of 20 µm or less, and a Na ion content of 0.35% by weight or less as Na ₂ O, (D) an adhesive component, and (E) A liquid silicone rubber composition for solvent-free coating comprising a platinum catalyst. The composition of claim 1 containing a silicone oil soluble alkenyl group-containing silicone resin. The coating composition according to claim 1 or 2, for airbag fabric. Fabric for airbags with a coating film formed by the composition of claim 3.